NEW YORK: Wall Street investment bank Merrill Lynch said on late Monday that Ahmass Fakahany plans to retire as co-president and chief operating officer, effective February 1.   

Fakahany, 49, joined the New York-based financial-services firm in 1987 and has served in a variety of senior roles. Merrill Lynch did not reveal the company's intentions for a successor.   

Fakahany is considered one of the architects of Merrill's development of high-risk investment vehicles, including those backed by subprime mortgages given to people with poor credit.   

The strategy helped rack up a 7.8 billion dollar net loss for the firm in 2007, compared with a net profit of 7.5 billion dollars in 2006.   

Financial troubles at Merrill, one of Wall Street's leading investment houses, led to the resignation of chief executive Stan O'Neal in late October.    

John Thain, a former head of the New York Stock Exchange, was recruited to succeed him.